Redirected from Wikipedia:Copyright
To fulfill the above goals, the text contained in Wikipedia is licensed to the public under the GNU Free Documentation License (GFDL). The full text of this license is at Wikipedia:Text of the GNU Free Documentation License.
The text of the GFDL is the only legally binding document; what follows is our interpretation of the GFDL: the rights and obligations of users and contributors.
If you want to use Wikipedia materials in your own books/articles/web sites or other publications, you can do so, but you have to follow the GFDL, which entails the following:
An example notice for an article that uses the Wikipedia article Foo might read as follows:
("Foo" and the Wikipedia URL must of course be substituted accordingly.)
Occasionally, Wikipedia articles may include images, sounds, or text quotes used under the "fair use" doctrine. In this case, the material will be identified as from an external source (on the image description page, or history page, as appropriate). However, what is fair for us to use may not be fair for your intended use of the media.
For example, if we include an image under fair use, you must ensure that your use of the article also qualifies for fair use (this might not be the case, for example, if you were using a Wikipedia article for a commercial use that would otherwise be allowed by the GFDL).
Wikipedia does use some text under licenses that are compatible with the GFDL but may require additional terms that we do not require for original Wikipedia text (such as including Invariant Sections, Front-Cover Texts, or Back-Cover Texts). When using these materials, you have to include those invariant sections verbatim.
If you contribute material to Wikipedia, you thereby license it to the public under the GFDL (with no invariant sections, front-cover texts, or back-cover texts). In order to contribute, you therefore must be in a position to grant this license, which means that either
In the first case, you retain copyright to your materials. You can later republish and relicense them in any way you like. However, you can never retract the GFDL license for the versions you placed here: that material will remain under GFDL forever. In the second case, if you incorporate external GFDL materials, as a requirement of the GFDL, you need to acknowledge the authorship and provide a link back to the network location of the original copy. If the original copy required invariant sections, you have to incorporate those into the Wikipedia article; it is however very desirable to replace GFDL texts with invariant sections by original content without invariant sections whenever possible.
If you use part of a copyrighted work under "fair use", or if you obtain special permission to use a copyrighted work from the copyright holder under the terms of our license, you must make a note of that fact (along with names and dates). It is our goal to be able to freely redistribute as much of Wikipedia's material as possible, so original images and sound files licensed under the GFDL or in the public domain are greatly preferred to copyrighted media files used under fair use. See Wikipedia:Boilerplate request for permission for a form letter asking a copyright holder to grant us a license to use their work under terms of the GFDL.
Never use materials that infringe the copyrights of others. This could create legal liabilities and seriously hurt the project. If in doubt, write it yourself.
Note that copyright law governs the creative expression of ideas, not the ideas or information themselves. Therefore, it is perfectly legal to read an encyclopedia article or other work, reformulate it in your own words, and submit it to Wikipedia. (See plagiarism and fair use for discussions of how much reformulation is necessary in a general context.)
Linking to copyrighted works is usually not a problem, as long as you have made a reasonable effort to determine that the page in question is not violating someone else's copyright. If it is, please do not link to the page. Whether such a link is contributory infringement is currently being debated in the courts, but in any case, linking to a site that illegally distributes someone else's work sheds a bad light on us.
It is not the job of rank-and-file Wikipedians to police every article for possible copyright infringement, but if you suspect one, you should at the very least bring up the issue on that page's talk page. Others can then examine the situation and take action if needed. The most helpful piece of information you can provide is a URL or other reference to what you believe is the source of the text.
There is a standard text for this notice that explains the situation to the poster in the Wikipedia:Boilerplate text page.
Some cases will be false alarms. For example, if the contributor was in fact the author of the text that is published elsewhere under different terms, that does not affect his right to post it here under the GFDL. Also, sometimes you will find text elsewhere on the web that was copied from Wikipedia. In both of these cases, it is a good idea to make a note in the talk page to discourage such false alarms in the future.
If a page really is an infringement, then the content will be deleted a note to that effect will be made on the talk page, along with the original source. If the author's permission is obtained later, it can be restored.
If a page consists of nothing but a suspected copyright infringement, then you can also list it on Wikipedia:Votes for deletion. If, after a week, the page still appears to be a copyright infringment, then it may be deleted following the procedures on the votes page.
In extreme cases of contributors continuing to post copyrighted material after appropriate warnings, such users may be blocked from editing to protect the project.